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Data Recovery & Solid State
theoverlay writes "With all of the recent hype about solid-state drives in both consumer applications and enterprise environments I have a real concern about data recovery on these devices. I know there are services for flash memory restoration but has anyone been involved in data restoration projects on ssd drives? What are the limits and circumstances that have surfaced so far? What tools will law enforcement and government use to retrieve data for investigations and the like?"
No, you can pick up the old signals even in new drives. It's more complicated now, since you need to know the encoding schemes and ECC strategy (there are some wild ones out there now with fancy LDPC structures and the like), the fact that media noise is actually the dominant factor in modern encoding schemes, and tracks are pretty tight. But if you're willing to go the distance you can pull stuff off. And if you're the NSA or a drive manufacturer you can go great guns and use a interferometer controlled spin stand to read the off track footprint from the slight servo misalignment of the head and track when you did the erase. Not cheap, not quick, but it'll usually work. We do stuff like that to make sure that overwriting performance is "good enough" to dominate the signal, but you can still see the old signal down in the noise if you need it badly enough.
Yeah, I work on the things. So what's your point? Nothing's changed so badly that a single write can wipe out the data completely unless you're very (un)lucky if you want it badly enough. You still have to overwrite a fair number of times to really wipe your disk.
And before you CS types go all whacko on best theoretical patterns for erasure, we encode your bits ourselves into our own codespaces and usually use sequencers to scramble the bits to whiten out the frequency bands for more typical input patterns, so without knowing what we're doing your efforts to optimize erasure are dubious at best.